1. Technical Field
The present disclosure relates to an optical input device in particular, to a wake up method of an optical input device and the optical input device using the same.
2. Description of Related Art
An optical mouse, typically includes a light source to illuminate a navigation surface and an image sensor that functions as a miniature digital camera to continually capture images of the illuminated navigation surface and to determine the speed and the direction of the optical mouse being moved across the surface through sequentially comparing frames of image information captured so as to control the movement of a cursor displayed on a monitor.
Recently, optical mice equipped with wireless technology, i.e., wireless optical mice, have been widely used for cursor control operation. A wireless optical mouse generally is battery powered i.e., the wireless optical mouse uses the equipped battery to supply the necessary operating power. The wireless optical mouse further is designed to incorporate power-saving feature such as automatically entering a sleep mode or a hibernate mode after being idled for a period of time and entering an active or a run mode when movement of the optical mouse has being detected so as to conserve power.
Existing methods such as pixmon wakeup algorithm, de-correlation algorithm, and surface quality (SQUAL) wakeup algorithm, are commonly adopted waking up algorithms for waking up the wireless optical mouse from sleep mode. However, method such as pixmon wakeup algorithm merely check for the maximum pixel value and minimum pixel value variation of any instantly captured frames while the wireless optical mouse operates in the sleep mode, hence may not accurately detect whether the wireless optical mouse has been moved. Methods such as the de-correlation algorithm and SQUAL wakeup algorithm on the contrary are much more accurate in movement detection as the former detects correlation between frames and the latter detects surface variation between frames, but both methods require complex and intense computations such as DCR filtering computation and image correlation which in terms consume more power from the battery.